Diversity in the reactions of unsymmetric dinucleating Schiff base ligands with CuII and NiII

A diversity of reaction products have been found in the reactions of two related unsymmetrical Schiff base dinucleating ligands, HL1 and HL2, derived from 3-chloromethyl-5-methylsalicylaldehyde 1, with copper(II) and nickel(II) salts. The ligands remain intact in the copper(II) complexes to give the homodinuclear complexes [(Cu2LBr3)-Br-1] 2 and [Cu2L2(OH)(ClO4)]ClO4 3, the crystal structures of which have been solved. The reactions of HL1 and HL2 with nickel perchlorate led to hydrolysis of the imine bond. With HL1 the homodinuclear complex [NiLA(OH2)](2)[ClO4](2). 4H(2)O was formed and with HL2 hydrolysis was followed by elimination of C2H4 from the terminal NEt2 of the iminic side arm to leave an NHEt group and the dinuclear complex [NiLC(OH2)](2)[ClO4](2). 3CH(3)OH. The crystal structures of the two nickel complexes are also reported.